Grammars and Parsers

Grammars are models of linguistic structure. Parsers are algorithms
that infer linguistic structure, given a grammar and a linguistic
expression. Conversely, given a "training" set of linguistic
expressions, we can attempt to learn grammars.

The Proteus Project encompasses three research efforts that explore
fundamental questions about the nature of linguistic structure and how
it can be exploited in NLP applications. The first is our publicly
available Apple Pie Parser for
English. The second is a newer syntactic parser built by discriminative training techniques. The third is a new effort on multi-dimensional grammars and
parsers for parallel texts. Such grammars are a kind of structured model of translational equivalence.